"Tout le bonheur du monde"
2016-11-05
Astronomy picture of the day - 2016 November 5 - ISS Fisheye Fly-Through
Image Credit: NASA, ISS, Harmonic
Explanation: Shot in Ultra HD, this stunning video can take you on a tour of the International Space Station. A fisheye lens with sharp focus and extreme depth of field provides an immersive visual experience of life in the orbital outpost. In the 18 minute fly-through, your point of view will float serenely while you watch our fair planet go by 400 kilometers below the seven-windowed Cupola, and explore the interior of the station's habitable nodes and modules from an astronaut's perspective. The modular International Space Station is Earth's largest artificial satellite, about the size of a football field in overall length and width. Its total pressurized volume is approximately equal to that of a Boeing 747 aircraft.
2016-11-03
Astronomy picture of the day - 2016 November 3 - NGC 253: Dusty Island Universe
Image Credit & Copyright: Dietmar Hager, Eric Benson
Explanation: Shiny NGC 253 is one of the brightest spiral galaxies visible, and also one of the dustiest. Some call it the Silver Dollar Galaxy for its appearance in small telescopes, or just the Sculptor Galaxy for its location within the boundaries of the southern constellation Sculptor. First swept up in 1783 by mathematician and astronomer Caroline Herschel, the dusty island universe lies a mere 10 million light-years away. About 70 thousand light-years across, NGC 253 is the largest member of the Sculptor Group of Galaxies, the nearest to our own Local Group of Galaxies. In addition to its spiral dust lanes, tendrils of dust seem to be rising from a galactic disk laced with young star clusters and star forming regions in this sharp color image. The high dust content accompanies frantic star formation, earning NGC 253 the designation of a starburst galaxy. NGC 253 is also known to be a strong source of high-energy x-rays and gamma rays, likely due to massive black holes near the galaxy's center.
2016-11-02
Astronomy picture of the day - 2016 November 2 - M27: The Dumbbell Nebula
Image Credit & Copyright: John Hayes
Explanation: The first hint of what will become of our Sun was discovered inadvertently in 1764. At that time, Charles Messier was compiling a list of diffuse objects not to be confused with comets. The 27th object on Messier's list, now known as M27 or the Dumbbell Nebula, is a planetary nebula, the type of nebula our Sun will produce when nuclear fusion stops in its core. M27 is one of the brightest planetary nebulae on the sky, and can be seen toward theconstellation of the Fox (Vulpecula) with binoculars. It takes light about 1000 years to reach us from M27, shown above in colors emitted by hydrogen and oxygen. Understanding the physics and significance of M27 was well beyond 18th century science. Even today, many things remain mysterious about bipolar planetary nebula like M27, including the physical mechanism that expels a low-mass star's gaseous outer-envelope, leaving an X-ray hot white dwarf.
2016-11-01
Astronomy picture of the day - 2016 November 1 - Arp 299: Black Holes in Colliding Galaxies
Image Credit: NASA, JPL-Caltech, GSFC, Hubble, NuSTAR
Explanation: Is only one black hole spewing high energy radiation -- or two? To help find out, astronomers trained NASA's Earth-orbiting NuSTAR and Chandra telescopes on Arp 299, the enigmatic colliding galaxies expelling the radiation. The two galaxies of Arp 299 have been locked in a gravitational combat for millions of years, while their central black holes will soon do battle themselves. Featured, the high-resolution visible-light image was taken byHubble, while the superposed diffuse glow of X-ray light was imaged by NuSTAR and shown in false-color red, green, and blue. NuSTAR observations show that only one of the central black holes is seen fighting its way through a region of gas and dust -- and so absorbing matter and emitting X-rays. The energetic radiation, coming only from the galaxy center on the right, is surely created nearby -- but outside -- the central black hole's event horizon. In a billion years or so, only one composite galaxy will remain, and only one central supermassive black hole. Soon thereafter, though, another galaxy may enter the fray.
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